The invention concerns a packaging machine that simultaneously processes two webs of packaging materials.
2. Information Disclosure Statement
Packaging machines are well known and come in a variety of configurations for achieving various packaging objectives. The single packaging machines generally wrap one article at a time or use an intricate folding method for the wrapping material to wrap two articles at a time. Other machines attempt to increase packaging production by basically combining two machines with one conveyor feed system. The following patents represent the variations on packaging machines which exemplify the art:
U.S. Pat. No. 3,581,457 issued to Gerlach concerns a wrapping machine in which a package is formed by transversely curling a single web, to enclose two laterally aligned and spaced articles, without overlapping the free edges of the web. Both edges are longitudinally sealed and then the web is transversely sealed and severed so that the finished package contains two individually enclosed articles.
U.S. Pat. No. 4,035,984 issued to Gerlach et al. concerns a machine for packaging a twin row of articles in a web of wrapping material by moving longitudinally and transversely, pairs of articles along two rows onto a moving web of wrapping material which is then folded over the articles to form two parallel tubes of articles with the longitudinal edge portions and a central portion of the web disposed between the tubes.
U.S. Pat. No. 4,269,016 issued to Kopp et al. concerns an apparatus where two separate streams of bags are formed. The successive bags of each stream are alternately deposited on two side-by-side tracks of conveyor, thus obtaining four partial streams of bags which are then successively conveyed to filling, sealing and discharge stations.
U.S. Pat. No. 4,662,978 issued to Oki concerns a transverse sealing mechanism for use in producing bag-packed products by packing products in tubular film. The device has a compression mechanism which provides for compression pressure on transversely sealed portions and a forcibly cooled cutting device which applies infinite compressive force to the compressed, cooled and cut region of the transversely sealed portion.
U.S. Pat. No. 5,058,364 issued to Seiden et al. discloses an intermittent motion packaging machine where pouches in an interconnected strip are advanced edgewise to a cut-off station where the leading pouch is severed from the strip, transferred to two opposing pouch clamps on two different chains and advanced broadwise through a filling station. Before being filled, the pouches are opened by shifting portions of the inboard runs of the two chains laterally toward one another, and by pulling the side panels of the pouch away from one another with suction cups.
U.S. Pat. No. 5,080,747 issued to Veix concerns a heat sealing mechanism with movable bars. Heat seal bars are located on opposite sides of an elongated strip of heat sealable material adapted to be advanced in a step by step motion. When the strip dwells, the bars are shifted linearly inwardly into engagement with the strip to form a heat seal and then the bars are retracted linearly away from the strip.
U.S. Pat. No. 5,155,979 issued to McDonald concerns a form-fill-seal apparatus for simultaneously packaging two streams of articles. A sheet of packaging material is brought around adjacent articles with a central portion of the material being passed between the streams of articles and between outer edge portions of the packaging material. The packaging material is sealed through the combined thicknesses of its central portion and its edge portions without introducing a sealing device between the articles.
U.S. Pat. No. 5,236,543 issued to Reidel concerns an apparatus for welding the sealing seam on a package which consists, at least partially, of synthetic plastics coated paper, comprising a welding tool having dies and counter dies, and a support and drive means to generate the pressure force.
U.S. Pat. No. 5,369,941 issued to Repparini relates to a packaging machine made up of two vertical packaging groups set on opposite sides of a central structure equipped with a horizontal bilateral station that carries out the transversal sealing of both resulting packets.
Notwithstanding the prior art in this field, it is believed that the present invention, which retrofit's existing single web intermittent motion packaging machines into dual web intermittent motion packaging machines in the particular fashion described herein, is neither taught nor rendered obvious.